It is known in the art that an internal combustion engine having a plurality of cylinder banks may be operated such that at least one first cylinder bank is at least partially able to be cut off.
In conventional methods for cylinder cut-off, the charge for the cylinders not to be cut off is already built up immediately before the cut-off of the cylinders to be cut off in a so-called transitional phase, that is, while the cylinder cut-off is still inactive. Thereby, the resulting torque that is output by the internal combustion engine would increase. However, in order to keep this torque constant, the angle of ignition is pulled to retardation or the fuel supply is partially blanked out. When the charge of the cylinders that are not to be cut off has reached the required setpoint value, the cylinder cut-off is activated and the ignition angle is pulled to advance again, to the optimal earlier value, or the partial blanking out of the fuel supply for the cylinders not to be cut off is revoked. In this way, the missing contribution to torque by the cut-off cylinders may be compensated for.
What is problematic with this approach is that, in the transitional phase immediately before the cut-off of the cylinders to be cut off, by pulling the ignition angle to retardation, an increase in fuel consumption and an increase in exhaust gas temperatures are caused. In this context, because of the increased exhaust gas temperatures, damage may result to a catalytic converter that is situated in an exhaust branch of the internal combustion engine.